In 40 parts

23 October 2014

Last Tuesday, Stephen Cleobury and the BBC Singers gave a sumptuous concert at Milton Court Concert Hall. As well as a gorgeous new piece by Ivan Moody, which also featured cellist Nicolas Altstaedt, there were four 40-part pieces on the programme: Alessandro Striggio’s Ecce beatem lucem, I have thee by the hand, O Man by Robin Walker, my own Sanctum est verum lumen and, of course, Thomas Tallis’s iconic Spem in alium.

I had always wanted to write a 40-part piece. But when I finally got the opportunity, for the Tallis quincentenary in 2005 (assuming that Tallis was indeed born in 1505), I realised to my horror that I had actually no idea what to do with those forty voices. Because the whole point of a 40-part piece is, of course, that it’s in forty parts! I didn’t find it all easy to come up with interesting ideas that necessitated forty voices. In the end, everything in Sanctum est verum lumen – the slow panning of material from left to right (or right to left), the closely-worked micropolyphony for all voices, the big block chords, the antiphonal exchanges between groups of voices – can be found in Spem in alium; I just expanded and re-imagined things that Tallis had invented.

I also hadn’t expected the logistics of writing a 40-part piece to be so problematic. For example, how do you voice a tutti 10-part chord? Four voices per note, obviously, but how to allocate them? Every tiny musical decision becomes vastly more complicated. Because I use 18-stave manuscript, three A3 sheets would have to be stuck together and the only surface that would accomodate them was the floor. In order to see the whole score on my computer screen any detail becomes impossible to make out. The huge amount of information in the score slowed my computer down so inputting notes and text took for ever. Despite that I couldn’t have composed Sanctum est verum lumen without it.

All of which made my admiration for Tallis’s achievement increase a millionfold! Not only did he not have any modern compositional aids, of course, he didn’t even have his own piece to study and learn from and be inspired by. I don’t know how many times I have heard Spem in alium over the years but it never loses its power to thrill. It is the most wonderful, extraordinary achievement.